Swanson (21-6 MMA, 6-2 UFC) was unable to prevent Edgar (18-4-1 MMA, 12-4-1 UFC) from taking him down, and he spent the majority of the contest on his back before succumbing to a fifth-round submission.

The 31-year-old never imagined he would lose to “The Answer” in such one-sided fashion, and he said the FOX Sports 1-televised main event revealed serious flaws in his game (watch the Edgar vs. Swanson video highlights).

“Obviously, it was super frustrating, but he did what he had to do, and he exposed me,” Swanson said on FOX Sports 1’s post-event show. “I was super confident. I thought I prepared, and I obviously underprepared.

“I want to thank him for the lesson. I’m going to be better.”

Swanson has struggled in the past with wrestlers, including recent title challengers Chad Mendes and Ricardo Lamas. He displayed improved takedown defense during his recent winning streak, but Edgar was able to connect with seven takedowns in the near-25-minute affair.

“(I learned) where my weaknesses are; he was able to expose it,” Swanson said. “I took this fight because I felt he was one of the best in the world at a lower weight class, and I wanted to test myself. I’m getting up there in age, and I wanted to see how bad I am. I know I took a beating, but I was still hopeful all the way to the end.”

Although he was taken down several times and absorbed more than 250 total strikes, Swanson did he best to stay competitive until the bitter end. Edgar was relentless, though, and was determined to get the finish.

The former UFC lightweight champion finally got it with a rear-naked choke with just four seconds remaining in the fifth round. It was the latest finish ever in a UFC bout, and while it’s a record Swanson would rather not be a part of, he said it’s better than a broken jaw.

“I took a lot of elbows on my jaw, so my jaw was pretty tired,” Swanson said of the submission. “When I kept turning, turning, turning I was like, ‘He is not going to finish me.’ Then my mouth was open, and he cranked my jaw pretty hard. I don’t want a broken jaw again. I’ve already lived through that, so, oh well.”

Despite the deflating loss, Swanson said he still believes in his potential to become the world’s best featherweight. He had his momentum halted by a former UFC titleholder, but it wasn’t enough to make Swanson give up.

“If you want to be the best, sometimes you get the raw end of the deal,” Swanson said. “That’s life.”